Resin composition



Patented July 27 1943 UNITED STATES PATENT OFFICE 2.22amv RESIN CORT-POSITION Elmer R. Derby, Springfield, Mass, assignor, by mesne assignments, to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Original application November 2,

1937, Serial No. 172,442. Divided and this application January 22, 1942, Serial No. 427,718

oily exudation or tiny droplets causing haze.

8 Claims.

My present invention relates to plastic material to be employed as interleaf material in the manufacture of safety glass and the like. As is well known to those skilled in the art, polyvinyl acetal resin, 1. e. a material made by condensing .an aldehyde with a partially hydrollzed polyvinyl satisfactory resin made with formaldehyde contains 82% acetal, 8% hydro yl group's figured as polyvinyl alcohol and 10% acetate. Another satisfactory resin contains from to 2% acetate,

16 to 20% hydroxyl groups figured as polyvinyl alcohol and the balance acetal formed with butyraldehyde. The different resins oi which the foregoing are only two examples have di'fierent properties according to the proportion of the three substituents mentioned and the particular aldehyde employed.

In a companion application Serial No. 172,443 filed Nov. 2, 1937, I have described the important discovery that the most satisfactory plasticizer of a given chemical series of plasticizers is that one which is most nearly incompatible with the particular resin employed and yet is miscible with it.

I have also discovered that certain substances, particularly esters, which are not themselves compatible with the resinin the proportions required for good quality plastic for safety glass, can be rendered compatible with polyvinyl acetal resin and will have the efiect of plasticizing the resin and of producing a material which is useful for the purposes specified provided there is also present in the mixture 9, suitable quantity of a second plasticizer which, in the proportion used is miscible both with the resin and the first plasticizer to produce a homogeneous plastic. It will be understood that when I refer to incompatibility of a plasticizer I realize that a very small amount of practically any plasticizeris 'miscible with these resins; but for safety glass a relatively large proportion of plasticizer is required and as the amount of plasticizer is increased a point is usually reached where further plasticizer refuses While the second plasticizer is often miscible in all proportions with the resin I have found quite unexpectedly that in some cases, as in Example 4 below, both plasticizers may be immiscible if used alone in the proportion required for good quality plastic for safety glass but a miscible mixture can be made in which the two plasticizers are so proportioned that the mixture is nearly incompatible in the amount required for good safety glass plastic.

As a result of this discovery I am able to use as plasticizers certain substances which have previously been rejected as plasticizer because of their incompatibility with the resin, also certain substances which have not been thought to be usable as plasticizers. butyl diglycollate is incompatible with 100 parts of a polyvinyl acetal resin made with formaldehyde and containing 82% acetal, 8% hydroxyl groups figured'as polyvinyl alcohol and 10% acetate, but if phenyl ethyl alcohol is addedin suf ficient quantity, for example, parts, even '50 parts of dibutyl diglycollate can be used successfully, obtaining miscibility and producing a satisfactory and useful product. For convenience, the plasticizer which is relatively incompatible with the resin may be referred to as the non-compatible plasticizer, and the other as the solvent plasticizer. The following are other specific examples of'mixtures embodying my invention:

1. Polyvinyl acetal resin made with formaldehyde and containing about 82% acetal, 8% hydroxyl. groups figured as polyvinyl alcohol. and 10% acetate, 100 parts, mixed with dibutyl phthalate 40 parts and phenyl ethyl alcohol 40 parts. Dibutyl phtlialate is normally incompatible with this polyvinyl acetal resin, but is rendered so by the phenyl ethyl alcohol.

2. The same polyvinyl acetal resin 100 parts, diglycol dibutyrate 50 parts and phenyl ethyl alcohol 2% to 5 parts. 'The diglycol dibutyrate is not compatible withthe acetal resin at 50 parts but 50 parts may be employed if combined with phenyl ethyl alcohol and the mixture is renderedentirely stable by the presence of 5 parts only of phenyl ethyl alcohol.

3. The same resin 100 parts. diglycol dipropionate 30 parts and butyl earbitol butyrate 30 parts. 60 parts of butyl carbitol butyrate alone are incompatible.

e. A polyvinyl acetal resin made with butyralto mix homogeneously, instead separating as an dehycle and containing 0 to 2% acetate, 16 to 20% For instance, 30 parts (11- hydroxyl groups figured as alcohol and the balance acetal. This resin 100 parts dilauryl phthalate 35 parts and diethylene glycol 5 parts.

5. The same polyvinyl acetal resin 100 parts, dilauryl phthalate 40 parts and dibutyl diglycollate 20 parts. 60 parts of dilauryl phthalate are incompatible.

6. The same resin 100 parts, amyl laurate 35 parts, dibutyl phthalate 25 parts. 35 parts of amyl laurate alone are incompatible with this resin.

'l. The same resin 100 parts, butyl laurate 35 parts, dibutyl phtlialate 25 parts.

8. The same resin 100 parts, amyl laurate 60 parts, phenyl ethyl alcohol 30 parts. 60 parts of amyl laurate alone, or 60 parts of amyl laurate plus 15 parts of phenyl ethyl alcohol, are incompatible.

9. The same resin 100 parts, butyl laurate 60 parts, phenyl ethyl alcohol 30 parts.

The proportions given above are thos which give the most satisfactory final product for the manufacture of safety, glass. due regard being had to both the cold break test and the hot break test as judged by dropping a two pound ball at 0 F. and 120 F., respectively, on an assembly made with plastic not less than 0.015 inch nor more than 0.027 inch thick. When used in laminated glass, each of the materials'produced in accordance with the foregoing examples gives ubstantially equal hot and cold break tests. The compositions mentioned give results superior to the present acetate safety glass and fully comparable with the compositions mentioned in the co-pending application mentioned and based on various polyvinyl acetal resins.

The laurates above mentioned may be pure chemical compounds or theesters of cocoanut oil fatty acids, or the esters of cocoanut oil fatty acids from which high boilers have been removed.

The present application is a division of my prior application, Serial Number 172,442 filed November 2, 1937.

What is claimed is:

l. A polyvinyl acetal resin plasticized with a. mixture of dilauryl phthalate and a member of the class consisting of diethylene glycol and dibutyl diglycollate.

2. A polyvinyl acetal resin made with butyraldehyde and plasticized with a. mixture of dilauryl phthalate and a member of the class consisting of diethylene glycol and dibutyl diglycollate.

3. A polyvinyl acetal resin plasticized with a mixture of dilauryl phthalate and diethylene glycol.

4. A polyvinyl acetal resin made with butyraldehyde and plasticized with a, mixture of dilauryl phthalate and diethylene glycol.

5. A polyvinylacetal resin made with butyraldehyde and plasticized with a mixture of substantially parts dilauryl phthalate and substantially 5 parts diethylene glycol for each 100 parts of resin.

6; A polyvinyl acetal resin plasticized with a mixture of dilauryl phthalate and dibutyl diglycollate.

7. A polyvinyl acetal resin made with butyraldehyde and plasticized with a mixture of dilauryl phthalate and dibutyl diglycollate.

8. A polyvinyl acetal resin made with butyraldehyde and plasticized with a mixture of substantially parts dilauryl phthalate and substantially 20 parts dibutyl diglycollate for each parts of resin.

ELMER R. DERBY. 

